1. Field
The present invention relates to a display substrate including a pad unit and a fan out unit that are disposed in a non-display area around a display area, on which an image is displayed, and a display apparatus including the display substrate.
2. Description of the Related Art
Portable, thin flat panel display apparatuses are widely used. Examples of flat panel display apparatuses include a light-receiving display apparatus, such as a liquid crystal display apparatus, and a light-emitting display apparatus, such as an organic light-emitting display apparatus and a plasma display apparatus.
The flat panel display apparatus may be partitioned into a display area (on which an image is displayed) and a non-display area around the display area. The display area and the non-display area may be on a substrate. A pad unit and a fan out unit may be disposed in the non-display area. The fan out unit is a portion that connects the pad unit and the display area, in which lines that transmit signals from a driver integrated chip (IC) mounted in the pad unit are provided.
The lines disposed in the fan out unit may have identical lengths. However, if a length of the pad unit is different from a length of an edge portion of the display area, lines disposed at two ends of the pad unit may be longer than those disposed at a center of the pad unit, and the lengths of the lines may linearly increase as they go from the center of the pad unit to the two ends of the pad unit. As the lengths of the lines increase or decrease linearly, and if resistance deviation between adjacent lines is not large, display quality does not degrade so much as to be recognizable by the naked eye.
However, if the pad unit includes a dummy pad that is not connected to a display area so that intervals between the lines are not uniform, and the pad unit is formed towards one side when compared to the display area, lengths of some lines disposed in the fan out unit increase or decrease non-linearly. Accordingly, resistance deviation between adjacent lines increases undesirably, and this resistance deviation causes degradation in display quality, which is recognizable by the naked eye.